1. Field of the Invention
The present invention relates to a vehicular brake hydraulic pressure control apparatus.
2. Description of the Related Art
When brakes are applied on a vehicle, such as an automatic four-wheel vehicle, the weight moves to the front wheels. As this phenomenon is significant for a vehicle with a high position of the center of gravity (a vehicle with a large weight transfer), it is possible for a vehicle with a large weight transfer to generate a large braking force, causing little slip of the front wheels.
On the other hand, a vehicle with a large weight transfer tends to cause weight swinging (pitching) during deceleration, and when the weight moves to the rear wheels the brake hydraulic pressure of the front wheels possibly become excessive to cause a slip.
As a known art, a technology for preventing such pitching is disclosed by Patent Document 1 (Japanese Patent No. 4529229). In the technology disclosed by Patent Document 1, the reference speed for a start of decreasing the pressure of the front wheels is adjusted to become higher, corresponding to the weight transfer, and the pressure decrease of the front wheels is controlled, while causing slipping. According to the technology by Patent Document 1, occurrence of an extreme weight transfer can be reduced.
However, in the technology disclosed by Patent Document 1, when strong braking operation is performed during low speed running, a large braking force is once generated and the front wheels are thereafter subjected to pressure decreasing control while causing a slip. Consequently, change in deceleration possibly becomes large to cause pitching.